announce_edge
announce_edge(vc, edge_left);
announce_edge(vc, edge_right);
announce_edge(vc, edge_top);
announce_edge(vc, edge_said);
announce_edge(vc, edge_bottom);
announce_edge(vc, edge_said);
announce_edge(vc, edge_top);
announce_edge(vc, edge_bottom);